Digger tooth construction



March 6, 1962 J. F. BRUNNER, JR 3,023,521

DIGGER TOOTH CONSTRUCTION Filed April '7, 1960 lose 6 f Bra/men, J12,

IN VEN TOR.

United States Patent 3,023,521 BIGGER TOOTH CONSTRUCTION Joseph F. Brunner, Jr., San Marino, Califi, assignor to Kay-Brunner Steel Products, Inc., a corporation of Delaware Filed Apr. 7, 1960, Ser. No. 20,645 3 Claims. (Cl. 37-142) My invention relates to an improved digger tooth construction for rooters, shovel dippers, dragline buckets, rippers, and the like, and particularly to that type of tooth construction which includes a socketed digging point detachably mounted on a tapered tang which in turn is fixed to a shank.

Specifically, my invention has to do with digger teeth in which the socketed point is interiorly formed with square side edges or corners, while the tang is formed exteriorly with beveled or rounded side corners or edges. Frequently, the tang edges are not made true from end to end or crosswise, and, as a consequence, a tight fit of the point on the tang cannot be made so that it becomes loose and ultimately splits. Also, when the tang edges are not made true the point as driven onto the tang assumes a cocked position thereon and, therefore, cannot travel square to the vertical plane of travel of the tooth shank which it must do for efficient digging and minimum distortion of the tooth.

It is a purpose of my invention to provide in a digger tooth construction a socketed point adapted to be used on a tang with rounded or beveled edges or corners, and wherein the point has its interior edges or corners relieved preferably on a radius to form grooves therein and whereby when the point is applied to a tang in which its edges, whether round or beveled, are not true, it insures a true fit of the point on the tang so that it occupies a position which is square to the intended vertical plane of travel of the shank of the digger tooth, and a tight fit which does not permit the point to become loose on the tang and resulting in splitting of the point.

It is also a purpose of my invention to provide in a digger tooth construction a point made of cast steel which possesses a certain resiliency such that when the point is driven onto the tang the grooved edges interiorly of the socket allow transverse expansion of the socket by the tang thus placing the walls of the socket under transverse tension which reacts to cause such walls to at all times tightly grip the tang and thus produce the best possible fit of the socket on the tang.

I will describe only one form of digger tooth construction embodying my invention and will then point out the novel features thereof in claims.

In the accompanying drawings:

FIG. 1 is a View showing in side elevation and partly in section one form of digger tooth embodying my invention.

FIG. 2 is an enlarged transverse sectional view taken on the line 22 of FIG. 1.

FIG. 3 is a substantially bottom plan view partly broken away.

FIG. 4 is an enlarged fragmentary sectional view taken on the line 4-4 of FIG. 1.

FIG. 5 is a view similar to FIG. 4 but showing a tang having a longitudinal edge or corner which is rounded in cross section as distinguished from the beveled edge tang shown in FIG. 4.

Referring more specifically to the drawings, in FIG. 1 is shown a conventional form of shank 15 rectangular in cross section and adapted at its upper end for mounting in any suitable manner on a rooter frame (not shown) or the frame of any other excavating implement, and

which provides a support for the digger tooth construction constituting my invention.

Integral with and extending forwardly from the lower end of the shank 15 is a tang 16 which is of conventional construction in that it is tapered forwardly to a squared transverse forward edge 17, and has upper and lower walls 18 and 19 and side walls 20 all of which converge to the edge 17.

Adjacent the junction of the upper face 18 of the tang and the forward face of the shank 15, the tang is undercut to provide a pocket 21 and a lip 22 at the center portion of the tang.

As is conventional in tangs of this form, the four longitudinal edges or corners thereof are either beveled transversely as at 23 in FIG. 3, or rounded transversely as at 24 in FIG. 5 to facilitate mounting of the digging point on the tang.

The digging point of my invention, indicated generally at 25, is of conventional construction to the extent that it comprises an upper plate 26, a lower plate 27 and side plates 28, and a digging tooth 29 which is of rectangular configuration in plan and sharpened at its forward end as at 30.

The plates 26, 27 and 28 coact to form therebetween a rearwardly-opening wedge-shaped recess or socket 31 for reception of the tang 16 therein in matching engagement therewith as shown in FIG. 1. The upper end of the top plate 26 is shaped to provide a lip 32 which is received in the pocket 21 to coact in providing an overlapped joint which is conventional.

Adjacent the wide end, the socket 31 has an opening 33 in the side plates 28 thereof which registers with an opening 34 in the tang 16, and through these openings a locking pin (not shown) of any suitable form is adapted to be extended for locking the point on the tang.

As shown in FIGS. 2, 4 and 5 the inner walls of the socket 31 are at their meeting edges or corners formed with grooves 35 each of which is substantially coextensive in length therewith and in cross section rounded on a radius such that the wall of the groove is spaced from the confronting beveled edge 23 or 24 of the tang. This leaves those converging sides of the tang adjacent the edge 23 free to move transversely into the groove. The lower lateral corner portions of the tooth 25 adjacent the rearward portions of the lower grooves 35 are bulged outwardly to form high strength resilient hinge-like means interconnecting the side plates 28 and lower plate 27.

Also the forward corner or edge wall of the socket 31 is formed with a groove 36 coextensive in length therewith and rounded transversely on a radius such that, as shown in FIG. 1, it is spaced from the confronting tang edge 17 leaving extending into the groove at the open side thereof the converging sides of the tang but spaced from the bottom of the groove and thus free to move thereinto.

The digging point, as distinguished from the conventional fabricated point, is cast as a unitary structure of steel and then tempered to a degree such that the four walls of the socket 31 possess the amount of resiliency for the purpose intended.

Thus it becomes apparent that as the digging point is driven onto the tang the beveled edges 23 or the rounded edges 24, as the case may be, as well as the squared end edge 17 act, by virtue of the grooves 35 and 36, as wedges to transversely expand the socket and thus place it under such tension as to obtain and maintain the best possible tight fit of the point on the tang and to thereby minimize, if not eliminate, the possibility of the point becoming loose on the tang and splitting.

Although I have herein shown and described only one form of digger tooth construction embodying my invention, it is to be understood that various changes and modifications may be made herein ,withoutdeparting from .the spirit of my invention and ,the spirit and scope of the appended claims.

What I claim is:

1. In combination, a one-piece digger tooth cast from resilient abrasion-resistant metal, said digger tooth having a pointed forward digging end, a V-shaped recess opening outwardly from the opposite rear end thereof and adapted to have a snug frictional press fit over a generally complementally shaped tang projecting forwardly from a supporting shank therefor, the lateral corner edges of said tang being relieved, and the juxtaposed interior corners of said digger tooth being bulged outwardly away from said lateral corners to provide arcuate semi-circular resilient hinge-like connections between the adjacent side walls of said tooth along the rear portion thereof, said semicircular resilient hinges cooperating with one another to hold the side walls of said recess resiliently and frictionally assembled to said tang, and detachable means passing through aligned holes in said tooth and in said tang for supplementing said resilient hinges in holding said tooth assembled to said tang.

2. In combination, a one-piece digger tooth formed of cast resilient metal, said tooth being generally V-shaped as viewed from the side thereof and having a V-shaped recess opening through the thick rear end thereof, the side and bottom walls of said recess being of substantially uniform thickness and being connected along the merging corner edges thereof by outwardly bulging hinge-like connections of arcuate configuration in cross section, said arcuate hinge-like connections being resilient and effective in storing stresses therein which stored stresses are available to maintain the side walls of said recess in powerful frictional contact with the complementally shaped-tang of a mounting shank when said digger tooth is press-assem bled to such a tang.

3. An article of manufacture comprising a one-piece resilient cast steel digger tooth of generally wedge-shape and having a generally wedge shape recess opening rearwardly through the thick end of said tooth and having its interior surfaces generally parallel to the adjacent exterior surfaces of said tooth, said tooth being characterized in that the interior lateral corners of said recess are cut away to provide arcuate channels for substantially the full length of said corners, and being further characterized in that a plurality of the lateral corner portions of said tooth bulge outwardly and form high strength resilient hinge means interconnecting the side walls of said recess and eifective in strongly resisting outward bulging of said side walls when said tooth is forcibly pressed onto a supporting tang having a shape complemental to the wedge shape of said tooth recess.

References Cited in the file of this patent UNITED STATES PATENTS 836,856 Bourque Nov. 27, 1906 1,188,480 Pemberton June 27., 1916 1,863,802 Norley June 21, 1932 1,885,326 Brune Nov. 1, 1932 2,139,446 Douglas Dec. 6, 1938 2,433,001 Mork Dec. 23, 1947 FOREIGN PATENTS 490,651 Canada Feb. 17, 1953 

